LC Analysis and Pharmacokinetic Study of Pachymic Acid After Intravenous Administration to Rats

A simple and sensitive high-performance liquid chromatographic method with UV detection was developed and validated to investigate the concentration of pachymic acid (PA) in rat plasma. The sample preparation was a liquid-liquid extraction and chromatographic separation was achieved with a Dikma Diamonsil^TM C₁₈ column (250 × 4.6 mm I.D.) with a C₁₈ guard column (8 × 4 mm I.D.) using a mobile phase consisting of MeOH-MeCN-aq. 0.45% H₃PO₄ (45:40:22) at a flow rate of 1.0 mL min^?1. The UV detection was at 210 nm. Standard curves were linear (r = 0.9998) in plasma over the concentration range of 0.5–50 μg mL^?1 and had acceptable accuracy and precision. Intra- and inter-day precisions expressed as the relative standard deviation (RSD) were 0.26–1.60% and 1.24–2.31%. The lower limit of quantification and lower limit of detection were 0.45 and 0.17 μg mL^?1. The method has been used successfully to study the pharmacokinetics of PA. After a dose of 30 mg kg^?1 by intravenous administration, the main pharmacokinetic parameters t _1/2, AUC_0-∞, CL, V_ss and MRT_0-∞ were 8.79 ± 6.80 h, 18.90 ± 9.39 μg h mL^?1, 0.53 ± 0.28 L h^?1, 5.60 ± 4.60 L and 12.58 ± 9.95 h, respectively.     

LC Method for Analysis of Three Flavonols in Rat Plasma and Urine after Oral Administration of Polygonum aviculare Extract

A high-performance liquid chromatographic method has been developed for the simultaneous analysis of the flavonols myricitrin (1), avicularin (2), and juglanin (3) in rat plasma and urine after oral administration of the total flavonoids from Polygonum aviculare. Samples were prepared by solid-phase extraction then separated on a C₁₈ reversed-phase column by use of a mobile-phase gradient prepared from methanol and aqueous formic acid solution. The flow rate was 1 mL min^?1. Detection was performed at 254 nm. The calibration range was 11–1,100 μg mL^?1 for both 2 and 3 in plasma; in urine the calibration ranges for 1, 2, and 3 were 32–1,600, 11–1,100, and 22–1,100 μg mL^?1, respectively. Intra-day and inter-day RSD were less than 4.33 and 3.62% for 2 and 3, respectively, in plasma, and no more than 4.03 and 2.22% for all the analytes in urine. The analytical sensitivity and selectivity of the assay enabled successful application to pharmacokinetic studies of flavonols 1–3 in rats.     

Metabolites of Icariin in the Gastrointestine of Rats Following Oral Administration

YinyanghuohasbeenusedasafolkmedicineforthousandsofyearsinChina.ItbelongstothegenusofEpimedium(Berberidaceae).ChinaPharmacopoeia(1995Ed.)collects5speciesofEpimedium,whereflavanoidsareregardedastheprincipalcomponentsresponsibleforthepharmacologicalactivitiesofYinyanghuo,suchasitstonic,antihypertensiveandantiinflammatoryactions.IcariinisoneofthemainflavonoidconstituentsinYinyanghuo"'andisextensivelyusedtocontrolthequalityofthecrudedrug"'.Inpreviouspapers"',wereportedtheisolationandidentificat…     

LC Determination of Icariside II in Rat Plasma and Tissues: Application to a Tissue Distribution Study

A sensitive and reliable reversed-phase liquid chromatography (RP-LC) with ultraviolet (UV) detection has been developed and validated for the quantification of Icariside II in rat plasma and tissues using Fermononetin as the internal standard. Protein precipitation and liquid?Cliquid extraction were utilized for plasma and tissue sample preparation, respectively. The analysis was successfully carried out on an Agilent SB-C₁₈ column (5 ??m, 4.6 × 250 mm) with the implementation of the following conditions: a mobile phase of phosphoric acid solution (0.1%, v/w)?CAcetonitrile (55:45, v/v), a flow rate of 1 mL min^?1, a column temperature of 25 °C and a detection wavelength of 270 nm. Good linear relationships of calibration curves were obtained (r ² > 0.9906) over the investigated concentration range with plasma and tissue samples. The lower limit of quantification (LLOQ) and the limit of detection (LOD) were 0.1 and 0.02 ??g g^?1, respectively (for plasma sample, they were 0.05 and 0.1 ??g mL^?1, respectively). The developed method which was embodied with good precision, accuracy, recovery and stability was corroborated to satisfy the requirements for biomedical sample analysis. This method has been successfully applied to tissue distribution study of Icariside II in rats after a single intravenous dose at 12.5 mg kg^?1. Results suggested that Icariside II was distributed to rat tissues rapidly with greater initial concentrations in kidney, lung and liver. Moderate initial distributions were obtained in rat muscle, heart, bone, spleen and plasma. Low amount of Icariside II was detected in testes, and no Icariside II could be detected in the brain.     

Pharmacokinetics and Tissue Distribution Study of Tryptanthrin in Rats by RP-HPLC with DAD Detector

A simple RP-LC-UV method was established for the determination of tryptanthrin in plasma and different tissues of rats. The separation was achieved by HPLC on a C₁₈ column with a mobile phases composed of acetonitrile?Cwater (47:53, v/v), UV detection was used at 251?nm. Good linearity was found between 0.0183?C1.1712???g?mL^?1 (r ²?=?0.999) for plasma and 0.0937?C1.7568???g?mL^?1 for the tissue samples, respectively (r ²????0.9932). The intra- and inter-day precisions expressed as the relative standard deviation for the method were 0.92?C6.01 and 1.06?C9.11?%, respectively. The relative recoveries of tryptanthrin ranged from 95.26 to 97.89?% for plasma and 82.55 to 114.99?% for tissue homogenates (except heart). The developed method was successfully applied to the pharmacokinetics and tissue distribution research after orally administration of a 56-mg?kg^?1 dose of tryptanthrin to healthy SD rats. The main pharmacokinetics distribution results showed that liver, lung, small intestine, and large intestine were the major distribution tissues of tryptanthrin in rats, and that tryptanthrin had difficulty in crossing the blood?Cbrain barrier.     

Pharmacokinetics and Tissue Distribution of Vinorelbine Bitartrate after Intraveous Administration of Liposomal and Injectable Formulations

A hydrophilic and temperature-induced degradation drug, vinorelbine bitartrate (VB)-loaded phosphatidylethanolamin liposomes (PSLs), was prepared by the thin-film hydration method. Liposomes were made of phosphatidylethanolamine: cholesteryl: oleic acid (PE: CHOL: OA, 3:3:1 mass/mass). The mean particle size of the PSLs ranged from 293.06 nm. The transmission electron microscope (TEM) images displayed that the shape of the PSLs was multilamellar vesicles with smooth surface. The highest entrapment efficiency (EE) and drug loading capacity (DL) could reach up to 68.5% and 6.23%, respectively. The PSLs was evaluated by comparing the rate of release of encapsulated VB in different phosphate buffer solution (PBS), and the result showed that the rate of drug release in acid medium was faster than in pH 7.4. Pharmacokinetic characteristics in vivo and the tissue distribution in mice were investigated, which provided experimental and theoretical basis for utilizing liposomes in malignant tumor chemotherapy.     

Insulin-Loaded SLN Prepared with the Emulsion Dilution Technique: In Vivo Tracking of Nanoparticles after Oral Administration to Rats

Insulin-loaded solid lipid nanoparticles (SLN) were prepared according to a solvent dilution method from O/W emulsions using isovaleric acid as organic phase. Insulin was derivatized with fluorescein isothyocianate (FITC) obtaining a fluorescent marker to be used in in vivo experiments. FITC-insulin and native insulin–loaded SLN were quite similar with regard to their mean sizes and encapsulation efficiency. SLN intestinal uptake was then investigated administering FITC-insulin loaded SLN on healthy male Wistar rats. Significant drug accumulation within intestinal lymphatic system was recovered, but the immune system seems to play an important role in SLN degradation: further studies are necessary to improve the results on blood glucose level.     

高效液相色谱-质谱联用技术测定鼻腔给药后人血浆中佐米曲普坦的含量

建立了经鼻腔给药后人血浆中佐米曲普坦的液相色谱-质谱联用测定方法。血浆样品经乙酸乙酯-二氯甲烷(体积比4∶1)液-液提取后,以Hypersil BDS C6H5柱(4.6 mm×250 mm,5μm)为色谱柱,流动相为乙腈(含1%甲酸)-0.02 mol.L-1醋酸铵(体积比30∶70),流速为0.6 mL.m in-1,柱温:25℃,进样量:40μL,在Agilent 1100 LC/MSD XCT离子阱质谱仪上,以选择离子监测(SIM)方式进行定量分析,用于监测的离子为m/z288(佐米曲普坦)和m/z296(舒马普坦,内标物)。佐米曲普坦的定量下限为0.30μg.L-1,线性范围为0.30~25μg.L-1,方法回收率在82%~87%之间(n=5),精密度与准确度符合生物样品分析要求。该法操作简便、快速、灵敏度高,可用于佐米曲普坦临床血药浓度和药代动力学研究。     

HPLC Analysis and Pharmacokinetic Study of Paeoniflorin after Intravenous Administration of a New Frozen Dry Powder Formulation in Rats

A simple and specific high performance liquid chromatographic (HPLC) method with UV detection using picroside II as the internal standard was developed and validated to determine the concentration of paeoniflorin in rat plasma and study its pharmacokinetics after an single intravenous administration of 40 mg kg^?1 paeoniflorin to Wistar rats. The analytes of interest were extracted from rat plasma samples by ethyl acetate after acidification with 0.05 mol L^?1 NaH₂PO₄ solution (pH 5.0). Chromatographic separation was achieved on an Agilent XDB C₁₈ column (250 × 4.6 mm I.D., 5 μm) with a Shim-pack GVP-ODS C₁₈ guard column (10 × 4.6 mm I.D., 5 μm) using a mobile phase consisting of acetonitrile–water–acetic acid (18:82:0.4, v/v/v) at a flow rate of 1.0 mL min^?1. The UV detection was performed at a wavelength of 230 nm. The linear calibration curves were obtained in the concentration range of 0.05–200.0 μg mL^?1 in rat plasma with the lower limit of quantification (LLOQ) of 0.05 μg mL^?1. The intra- and inter-day precisions in terms of % relative standard deviation (RSD) were lower than 5.7 and 8.2% in rat plasma, respectively. The accuracy in terms of % relative error (RE) ranged from ?1.9 to 2.6% in rat plasma. The extraction recoveries of paeoniflorin and picroside II were calculated to be 69.7 and 56.9%, respectively. This validated method was successfully applied to the pharmacokinetic study of a new paeoniflorin frozen dry power formulation. After single intravenous administration, the main pharmacokinetic parameters t _1/2, AUC_0-∞, CL_TOT, V _Z, MRT_0-∞ and V _ss were 0.739 ± 0.232 h, 43.75 ± 6.90 μg h mL^?1, 15.50 ± 2.46 L kg^?1 h^?1, 1.003 ± 0.401 L kg^?1, 0.480 ± 0.055 h and 0.444 ± 0.060 L kg^?1, respectively.     

LC with Fluorescence Detection for the Tissue Pharmacokinetics of 2-Methoxyestradiol Solution and Liposome After Intravenous Administrations to Rats

2-Methoxyestradiol is currently in phase II clinical trials as a chemotherapeutic agent. An LC method with fluorescence detection was developed for determination of methoxyestradiol in rat lung. Sample was extracted with ethyl acetate and separated on a C₁₈ column (150 mm × 4.6 mm, 5 μm) with a mobile phase consisting of potassium dihydrogen phosphate-acetonitrile-triethylamine (55:45:0.3, v/v/v, pH 3.0). The excitation and emission wavelength were set at 285 and 325 nm, respectively. Standard curves were linear over the concentration range of 0.25–64 μg g^?1. The method was found to be precise, accurate and specific and can be applied to tissue pharmacokinetics of methoxyestradiol in rats.     

Metabolites of Icariin in Urine Following Oral Administration

YinyanghuohasbeenusedinfolkmedicineforthousandsofyearsinChina.ItbelongstoplansofgenusEpimedinm(Berberidaceae).ChinaPharmcopoeia(l995Ed.)c0llectedfivespeciesofEpAnedium,inwhichflavanoidsareregardedastheprinciPalcomPonentsresponsibleforthePharmacologicalactivitiesofYinyanghuo,suchastonic,anti-hyPertensiveandami-inflarnmatoryactions.Icariinisoneofthemainflav0n0idconstituentsinYinyanghuo"'andextensivelyusedtocontrolthequalityofthecmdedrug."'TherearemanyrePortsonthepharmac0l0gical,chendcaland…     

Microcomputer Simulation of Eluite Distribution After LC Injection

Abstract

Equilibrium distribution theory was applied to the injection of eluite into several theoretical plates at the head of the column. The use of microcomputer spreadsheet software showed that a symmetric peak quickly develops despite an initial skewed distribution of eluite.     

黄芪口服液降低大鼠顺铂毒性作用机制的尿液代谢组学研究

采用基于液相色谱-飞行时间质谱联用(LC-TOF-MS)技术的代谢组学方法,分析大鼠尿液内源性代谢物的变化,研究黄芪口服液(HO)降低大鼠顺铂(CDDP)毒性的作用机制.采用低剂量多次腹腔注射CDDP的方法建立CDDP染毒大鼠模型,并连续给予16天HO.于第18天收集正常对照(Control)组、顺铂模型(CDDP)组和黄芪口服液(HO)组大鼠的24 h尿液, 进行LC-TOF-MS分析,以获取尿液代谢物组数据集,对所得数据进行主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA)等多元统计分析,以筛选潜在生物标志物.于第20天采集大鼠血清测定肌酐和尿素氮水平.血清指标测定结果表明, HO可以显著降低CDDP染毒大鼠的肌酐和尿素氮水平(p<0.05).PCA得分图显示,3组可分别聚类,HO组位于Control组和CDDP组中间,表明HO可部分改善CDDP所致大鼠尿液代谢产物的异常变化.综合OPLS-DA分析、t检验和倍数变化分析结果,最终共筛选并初步鉴定出35个尿液代谢产物作为HO减毒相关的潜在生物标记物.代谢通路分析结果表明,HO可通过纠正体内氨基酸代谢、能量代谢和核苷酸代谢等通路的紊乱,降低CDDP所致机体毒性.     

Metabolites of Icariin in Rat Bile Following Oral Administration

Yinyanghu0hasbeenusedasafolkmedicineforthousandsofyearsinChina.ItbelongstoplantSofgenusEpimedium(Berberidaceae).ChinaPharmacopoeia(l995Ed.)collectS5speciesofEpimedium,inwhichflavanoidsareregardedasprincipalcomP0nentsresponsibleforthepharmacologicalactivitiesofYinyanghu0,suchastonic,antihypertensiveandantiinflanunatoryactions.IcariinisoneofthemainflavonoidconstituentSinYinyanghuo"'andextensivelyusedtocontrolthequalityofthecrudedrug"'.Asapartofourstudiesonthebi0l0gicalfateoficariin(datanots…     

Simultaneous LC Determination of Quercetin, Kaempferol and Isorhamnetin in Rabbits after Intragastric Administration of an Ethanol Extract from Pollen Typhae

A simple and rapid reversed-phase LC method was developed and validated for simultaneous determination of three flavonoids, quercetin (QU), kaempferol (KA) and isorhamnetin (IS), in rabbit blood plasma. The plasma was deproteinized using 10% trichloroacetic acid and extracted by n-butanol–acetoacetate solvent prior to LC analysis. The analyte was separated on a reversed-phase column with acetonitrile and 0.1% phosphoric acid in water (27:73, v/v) as mobile phase at a flow-rate of 0.8 mL min^?1, and UV detection wavelength at 369 nm. By this developed method, the concentrations of QU, KA and IS were linearly related to their responses in the range of 0.05–2.5 μg mL^?1. The precision and accuracy for QU, KA and IS in plasma were within ±15% except for the limit of quantitation (LOQ), where they were within ±20%. The validated method has been successfully applied in the pharmacokinetic study of QU, KA and IS in rabbits after intragastric administration of an ethanol extract from traditional Chinese medicine Pollen Typhae.     

Simultaneous Determination of Danshensu and Puerarin in Rat Plasma by LC-MS-MS and Its Application to a Pharmacokinetics and Bioequivalence Study after Oral Administration of Tongmai Dripping Pill and Tongmai Oral Solutions

The active components danshensu (DS) and puerarin (PA) of Tongmai dripping pills (TDP) and oral solution (TOS) were detected in rat plasma after liquid–liquid extraction and oral administration of formulated TDP and TOS. Simultaneous determinations were carried out using electrospray negative ionization mass spectrometry in multiple reaction monitoring mode. The corresponding ion transitions selected for quantitation of DS and PA were at m/z 197.1, 135.0 and m/z 415.2, 294.9, respectively. 3,4-Dihydroxybenzoic acid was used as the internal standard and was monitored at m/z 153.1, 108.9. The linear calibration curves ranged from 9.56 to 637.00 ng mL^?1 and 9.02 to 601.00 ng mL^?1 for DS and PA, respectively. The lowest detectable limit and the lowest quantification limit for both DS and PA in rat plasma were 2.00 and 9.00 ng mL^?1, respectively. The intra-day precision of the assay was less than 10.7% and 8.99% for DS and PA and inter-day precision was less than 14.8% and 14.2% for DS and PA, respectively. The accuracy ranged from 80.56 to 115.3% and 86.91 to 110.6% for DS and PA. This analytical method was applied to a pharmacokinetics and bioequivalence study of DS and PA. Statistical and bioequivalence analyses of DS and PA data for AUC_0–24h and C _max revealed that the 90% confidence intervals for the mean ratio (T/R) of DS and PA for AUC_0–24h and C _max were 91%–106% and 98%–116%, respectively.     

用偶合反应化学发光法研究丹皮酚在兔体内的药物代谢动力学

为了研究丹皮酚的药物代谢动力学，采用高灵敏的偶合反应化学发光法，对兔血中的血药浓度进行监测，在ｐＨ为９．２的介质中，以Ｈ２Ｏ２氧化丹皮酚的反应与Ｌｕｍｉｎｏｌ－Ｈ２Ｏ２－ＣＯ＾２＋化学发光反应相偶合，测得牡丹皮和徐长卿中丹皮酚在兔体内的吸收速率分别为２．０７和０．４９９ｈ＾－１，消除半衰期分别为１１．７６和３．０４ｈ，相对而言牡丹皮所含丹皮酚具有吸收快、消除慢、生物利用度大的优点。     

A GC-SIM-MS Method for the Determination of Butylidenephthalide in Rat Plasma and Tissue: Application to the Pharmacokinetic and Tissue Distribution Study

Abstract

Butylidenephthalide is one of the major active components isolated from Rhizoma Chuanxiong. This paper describes a simple, rapid, specific and sensitive method for the quantification of butylidenephthalide in rat plasma and tissue distribution using a liquid-liquid extraction procedure followed by capillary gas chromatography-selected ion monitoring mode-mass spectrometry (GC-SIM-MS) analysis. The calibration curves were linear over the concentration ranging from 0.02–10.0 µg/mL (r > 0.99) for plasma samples and 0.18–7.25 µg/g (r > 0.99) for the tissue samples. The limit of quantification (LOQ) was 1.0 ng/mL or 1.0 ng/g (ten times signal/noise ratio). Within- and between-day precisions expressed as the relative standard deviation (RSD) for the method were 2.39–2.98% and 2.97–4.26%, respectively. The methods of recovery for all samples were greater than 80% at the low, medium, and high concentrations. The method has been successfully applied to a pharmacokinetics study in rats after an oral administration of Butylidenephthalide with a dose of 20.0 mg/kg. The main pharmacokinetic parameters obtained were T _max  = (0.22 ± 0.06) h, C _max = (3 ± 1) µg/mL, AUC = (32 ± 6) h?µg/mL, and K _a  = (8.5 ± 0.8)/h. The results showed that the butylidenephthalide was easily absorbed. The concentrations of butylidenephthalide in rat kidney, lung, heart, and cerebellum were higher than those in other organs. To determine free fraction in serum, samples were filtered using ultrafiltration membranes with a molecular weight cut-off of 10,000 Da and extracted using liquid-liquid extraction. The extracts were evaporated and analyzed by GC-MS. The protein binding in rat plasma, human plasma, and human serum albumin were 83 ± 4%, 94 ± 3%, and 89 ± 3%, respectively.